Apr 2, 2013

Apple pest makes first appearance in North America

USDA’s Animal and Plant Health Inspection Service (APHIS) has been notified by the Canadian Food Inspection Agency (CFIA) that it has detected apple proliferation phytoplasma (APP) in an apple orchard near Kentville, Nova Scotia. The affected orchard has been placed under quarantine. This is the first APP detection in North America.

The affected trees are Pacific Gala, and were imported into Canada from the United States in 2008. It is important to note that no symptoms of APP have been observed in the source nurseries or reported in the United States at large, and the source of infestation is unknown at this time. APHIS has provided trace forward information to CFIA, and is currently conducting testing at the source nurseries. At this time, CFIA has not imposed new restrictions on importation of apple trees from the United States, according to USDA.

APP is considered to be a quarantine pest in both Canada and the United States. It is present throughout Europe, where it is considered to be one of the most critical diseases of apple trees. APP is spread through propagation practices with infected material including budding and grafting. Long-distance dispersal of APP occurs through the trade of infected rootstock, scionwood or budwood. Specific insects, including certain psyllids, froghoppers and leafhoppers, also spread APP, but it is not transmitted through seed or fruit or pruning, according to USDA.

Symptoms of APP include shoots around axillary buds, which create a broom-like appearance at the end of affected branches; leaf resetting; enlarged leaf stipules; reduced growth and smaller, less sweet fruit.

For more information, email Craig Southwick, or call 970-494-7578.